Hannover 2016 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 16: Molecular Clusters

MO 16.1: Hauptvortrag

Donnerstag, 3. März 2016, 11:00–11:30, f142

Vibrational spectra, structures, and chemical bonding of silicon hydride cluster cations — •Otto Dopfer — Institut für Optik und Atomare Physik, TU Berlin

Silanes and their derivatives and ions are fundamental species in a variety of chemical disciplines. In contrast to hydrocarbon ions (CxHy+), almost no information is available for the corresponding SixHy+ cations. Here, IR spectra of SixHy+ cations produced in a supersonic plasma molecular beam expansion of SiH4 are inferred from photodissociation of cold Ne and Ar complexes obtained in a tandem quadrupole mass spectrometer coupled to an electron impact ionization source and an octopole ion trap. In addition, the clusters are characterized in their ground electronic states by quantum chemical calculations to investigate the effects of ionization and Ar/Ne complexation on their geometric, vibrational, and electronic structure [1-3]. We present initial results for Si2H6+, Si2H7+ and Si3H8+, which have complex potential energy surfaces, with low-energy isomers featuring unusual three-center two-electron (3c-2e) bonding. The IR spectrum of disilanium, Si2H7+, a fully H-passivated Si2 core with a Si-H-Si bridge is described by a 3c-2e bond. The excess proton in the Si-H-Si bridge generates three additional fundamentals, which provide the fingerprint of the 3c-2e bond. New results on protonated silanols will be presented.

[1] Savoca, George, Langer, Dopfer, PCCP 15, 2774 (2013). [2] Savoca, Langer, Dopfer, Angewandte Chemie 125, 1376 (2013). [3] George, Savoca, Dopfer, Chem. Eur. J. 19 45 (2013).